Display device and projection device

Abstract

The invention provides a display device and a projection device. The display device includes: a light source unit that irradiates light; a first display element; and a second display element. The display device is further provided with a light separating and combining member that separates the light irradiated by the light source unit into first light and second light having different wavelength bands, causes the first light to be emitted to the first display element, and causes the second light to be emitted to the second display element. The first light reflected and modulated by the first display element and the second light reflected and modulated by the second display element are combined. The display device is further provided with a light absorbing member that covers a portion of the first display element and absorbs a portion of the modulated second light reflected by the second display element and toward the first display element.

Description

[0001] This application is a divisional application of the application with the application number "202011555547.X", the application date of December 24, 2020, and the invention title of "Display Device and Projection Device". Technical Field

[0002] The present disclosure relates to, for example, a display device and a projection device including the display device.

[0003] A display device and a projection device using a DMD (Digital Micromirror Device) driven with respect to two orthogonal axes are disclosed in International Publication No. 2015 / 194454. Background Art

[0004] A display element included in a display device generates image light by reflecting incident light in accordance with an image signal. If a part of the generated image light enters other display elements as stray light, a part of the stray light is reflected. However, the unreflected stray light heats the periphery of the display element and degrades the display performance. Summary of the Invention

[0005] An object of the present disclosure is to provide a display device and a projection device that suppress an increase in the temperature of a display element due to stray light irradiated onto the display element.

[0006] The display device of the present disclosure includes: a light source unit that irradiates light; a first display element having a first light modulation unit that modulates and reflects incident light; and a second display element having a second light modulation unit that modulates and reflects incident light. The display device further includes a light separation and synthesis member that separates the light irradiated by the light source unit into first light and second light having different wavelength bands, emits the first light to the first display element, emits the second light to the second display element, and synthesizes the first light reflected and modulated by the first display element and the second light reflected and modulated by the second display element. The display device further includes a light absorption member that covers a part of the first display element other than the first light modulation unit and absorbs a part of the modulated second light that is reflected by the second display element and travels toward the first display element.

[0007] The projection device of the present disclosure includes: the display device; and a projection lens unit that projects image light emitted from the display device.

[0008] According to the present disclosure, a display device and a projection device that suppress an increase in the temperature of a display element can be provided. Brief Description of the Drawings

[0009] Figure 1 It is a diagram showing the structure of a projection device including the display device in the embodiment.

[0010] Figure 2 It is a diagram of a phosphor wheel used in the projection device in the embodiment.

[0011] Figure 3 It is a graph showing the transmittance of a dichroic mirror used in the projection device in the embodiment.

[0012] Figure 4 It is a perspective view of an optical separation and synthesis member used in the display device in the embodiment.

[0013] Figure 5 It is a side view of an optical separation and synthesis member used in the display device in the embodiment.

[0014] Figure 6 It is a perspective view of an optical separation and synthesis member used in the display device in the embodiment.

[0015] Figure 7 It is a perspective view of an optical separation and synthesis member used in the display device in the embodiment.

[0016] Figure 8 It is a perspective view of an optical separation and synthesis member used in the display device in the embodiment.

[0017] Figure 9 It is a perspective view of a light absorption member and a DMD used in the display device in the embodiment.

[0018] Figure 10 It is a top view of a light absorption member used in the display device in the embodiment.

[0019] Figure 11 It is a top view of a light absorption member used in the display device in the modified example.

[0020] Figure 12 It is a top view of a light absorption member used in the display device in the modified example. Detailed Embodiment

[0021] The embodiments will be described in detail below with appropriate reference to the accompanying drawings. However, sometimes a more detailed description than necessary may be omitted. For example, sometimes a detailed description of well-known matters and a repeated description of substantially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art.

[0022] In addition, the inventors have provided the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and the intention is not to limit the subject matter described in the claims by these.

[0023] (Embodiment)

[0024] The following uses Figures 1 to 10 to illustrate the implementation manner.

[0025] [1-1. Structure]

[0026] [1-1-1. Overall structure]

[0027] Figure 1 FIG. is a diagram for explaining the structure of the optical system of the projection device 1 equipped with the display device 3 of the present disclosure. For the convenience of the following description, in Figure 1 the XYZ orthogonal coordinate system shown in the figure is taken.

[0028] The projection device 1 includes: a display device 3; and a projection lens unit 80 that projects the image light emitted from the display device 3. The display device 3 includes: a light source unit 10 that irradiates white light; a light guide unit 40 that guides the white light irradiated from the light source unit 10; a display unit 50 that generates image light from the white light guided by the light guide unit 40; and a control unit 70 that controls the display unit 50.

[0029] First, the light source unit 10 will be described. The excitation light source, that is, the laser light source 11, is, for example, a blue semiconductor laser that emits blue light in a wavelength range of 447 nm to 462 nm and emits linearly polarized light. The laser light source 11 includes a plurality of semiconductor lasers in order to achieve a high-brightness display unit 50. The laser light source 11 includes a plurality of blue semiconductor lasers 11a arranged in a matrix on a plane. In Figure 1 five blue semiconductor lasers 11a are simply shown side by side as an example. In Figure 1 they are shown arranged with the polarization direction of the blue semiconductor laser 11a as the S polarization light Ps in the Y-axis direction as an example.

[0030] The excitation light, that is, the laser light emitted from each laser light source 11, is collimated by the corresponding collimating lens 12 respectively. The light emitted from the collimating lens 12 becomes substantially parallel light. The entire light beam of this parallel light is condensed by the lens 13 and is made substantially parallel again by the lens 14.

[0031] The laser beam made substantially parallel in the lens 14 is irradiated onto a quarter-wave plate 16 arranged at a given angle of rotation with respect to the X axis after passing through the diffusion plate 15. The laser light becomes elliptically polarized light by passing through the quarter-wave plate 16 and is incident on a dichroic mirror 17 arranged at approximately 45 degrees with respect to the optical axis.

[0032] The diffusion plate 15 is a glass plate. A diffusion surface with fine irregularities is formed on one side of the diffusion plate 15. In Figure 3Shows the spectral transmittance of the dichroic mirror 17. Regarding blue light, the wavelengths at which the transmittance becomes 50% are 465 nm for S-polarized light Ps and 442 nm for P-polarized light Pp. The colored light containing green and red components transmits through the dichroic mirror 17 with a transmittance of 96% or more.

[0033] The S-polarized light Ps component of the laser incident on the dichroic mirror 17 in the -X direction in the figure is reflected by the dichroic mirror 17 and exits in the -Z direction in the figure. The P-polarized light Pp component of the laser transmits through the dichroic mirror 17 and exits in the -X direction in the figure. The laser exiting in the -Z direction is condensed by the lens 18 and the lens 19, and the phosphor formed on the phosphor wheel device 30 is excited.

[0034] The phosphor wheel device 30 includes, as shown in (a) of the side view Figure 2 : a motor 31; and a rotating base material 32 including a disk-shaped plate body that is rotationally driven about the rotation axis of the motor 31.

[0035] On the rotating base material 32, as shown in (b) of the front view Figure 2 a yellow phosphor portion 33 is formed on the circumference at a distance R1 from the center A of the rotation axis of the phosphor wheel device 30, with a given width W inside and outside the circumference.

[0036] If the laser from the laser light source 11 is condensed on the yellow phosphor portion 33 of the phosphor wheel device 30, the yellow phosphor portion 33 is excited and emits yellow light as fluorescence.

[0037] Returning to Figure 1 , the yellow light obtained in the phosphor wheel device 30 exits from the phosphor wheel device 30 in the +Z direction. The fluorescence exiting from the yellow phosphor portion 33 in the -Z direction is reflected by the rotating base material 32 and exits in the +Z direction. These yellow lights are parallelized by the lenses 19 and 18 and transmit through the dichroic mirror 17.

[0038] On the other hand, the P-polarized light Pp of the blue light of the blue semiconductor laser after passing through the dichroic mirror 17 is condensed by the lens 20, transmits through the quarter-wave plate 21 and becomes circularly polarized light. The circularly polarized blue light is reflected by the mirror 22 disposed near the focus of the lens 20, and transmits through the quarter-wave plate 21 again to become S-polarized light Ps. The blue light that has become S-polarized light Ps passes through the lens 20 to become substantially parallel light and is reflected by the dichroic mirror 17.

[0039] In this way, the yellow light from the phosphor wheel device 30 and the blue light reflected by the mirror 22 are synthesized in the dichroic mirror 17 and exit as white light. The exiting white light is condensed by the condenser lens 23 and incident on the light guide portion 40.

[0040] The light guide unit 40 includes a rod integrator 41, lenses 42, 43, a mirror 44, and a lens 45. The light emitted from the condenser lens 23 of the light source unit 10 is incident on the rod integrator 41.

[0041] The light emitted from the rod integrator 41 is incident on the display unit 50 after passing through the lenses 42, 43, the mirror 44, and the lens 45.

[0042] The control unit 70 controls the rotation of the micromirrors of the respective DMDs 55, 57, 59 of the display unit 50 in accordance with the video content. The control unit 70 can be implemented by semiconductor elements or the like. For example, the control unit 70 can be composed of a microcomputer, CPU, MPU, GPU, DSP, FPGA, or ASIC. The function of the control unit 70 can be constituted only by hardware, or can be realized by combining hardware and software. The control unit 70 has a storage unit such as a hard disk drive (HDD), SSD, and memory, and realizes a given function by reading out the data and programs stored in the storage unit and performing various arithmetic processes.

[0043] The projection lens assembly 80 includes a plurality of lenses that magnify the image light emitted from the display device 3. The projection lens assembly 80 can use existing devices.

[0044] [1-1-2. Structure of the main part]

[0045] Next, with reference to Figure 1 、 Figure 4 and Figure 5 the structure of the display unit 50 will be described. Figure 4 is a perspective view of the light separation and synthesis member 53 used in the display unit 50 in the embodiment. Figure 5 is a side view of the light separation and synthesis member 53 used in the display unit 50. The display unit 50 includes a light guide prism 51, a light separation and synthesis member 53, a DMD 55 as a first reflective display element, a DMD 57 as a second reflective display element, a DMD 59 as a third reflective display element, and a light absorption member 61.

[0046] The light emitted from the lens 45 of the light guide unit 40 is incident on the light guide prism 51. The light incident on the light guide prism 51 is reflected within the light guide prism 51 to change the traveling direction of the light, and is emitted to the light separation and synthesis member 53.

[0047] The light separation and synthesis member 53 has: a function as a light separation member that separates incident white light into predetermined wavelength bands; and a function as a light synthesis member that synthesizes a plurality of lights separated into predetermined wavelength bands. The light separation and synthesis member 53 includes, for example, a first prism 91, a second prism 93, and a third prism 95. These first prism 91, second prism 93, and third prism 95 are integrated.

[0048] The white light incident from the light guide prism 51 is incident on the first surface 91a of the first prism 91. The first prism 91 has, for example, a triangular prism shape and has the first surface 91a on which the white light is incident. Further, the first prism 91 has: a second surface 91b that is connected to one side 91aa of the first surface 91a and extends in parallel opposite to the DMD 55; and a third surface 91c that is connected to one side 91bb of the second surface 91b opposite to the side 91aa and is in contact with the second prism 93. The first surface 91a, the second surface 91b, and the third surface 91c each have a rectangular shape.

[0049] A thin film such as a dielectric multilayer film is formed on the third surface 91c of the first prism 91, and the third surface 91c of the first prism 91 has the function of a dichroic mirror. Therefore, the white light incident on the first prism 91 is separated into light of each wavelength band of each color, such as a red wavelength band, a green wavelength band, and a blue wavelength band, on the inner surface of the first prism 91.

[0050] The wavelength band of the red light as the first light is, for example, 600 nm or more and 730 nm or less. The wavelength band of the green light as the second light is, for example, 515 nm or more and 599 nm or less. The wavelength band of the blue light as the third light is, for example, 420 nm or more and 514 nm or less.

[0051] The second prism 93 has, for example, a triangular prism shape and is adjacent to the first prism 91 and the third prism 95, respectively. The second prism 93 has a fourth surface 93a that is in contact with the third surface 91c of the first prism 91. Further, the second prism 93 has: a fifth surface 93b that is connected to one side 93aa of the fourth surface 93a and extends in parallel opposite to the DMD 57; and a sixth surface 93c that is connected to a side 93ab opposite to the side 93aa of the fourth surface 93a and is in contact with the third prism. The fourth surface 93a, the fifth surface 93b, and the sixth surface 93c each have a rectangular shape.

[0052] The third prism 95 has, for example, a trapezoidal prism shape and is adjacent to the second prism 93. The third prism 95 includes: a seventh surface 95a that is in contact with the sixth surface 93c of the second prism 93; and an eighth surface 95b that is opposite to the seventh surface 95a and the DMD 59 and extends in parallel.

[0053] The red light separated by the first prism 91 passes through the second prism 93, exits from the light separation and synthesis member 53, and is incident on the DMD 57. Similarly, the separated blue light passes through the second prism 93 and the third prism 95, exits from the light separation and synthesis member 53, and is incident on the DMD 59. Similarly, the separated green light is totally reflected on the first surface 91a and then exits from the light separation and synthesis member 53 and is incident on the DMD 55.

[0054] Next, refer toFigure 5 , Figure 6 。 Figure 6 is a perspective view of the light separation and synthesis member 53 used in the display unit 50 in the embodiment, showing the optical path of the blue image light Pb reflected by the DMD 59. In addition, in Figure 6 , the light absorption member 61 is omitted for easy understanding of the optical path.

[0055] The blue image light Pb generated by reflection from the DMD 59 passes through the third prism 95 and the second prism 93 and enters the first prism 91. The blue image light Pb that has passed through the third surface 91c of the first prism 91 is combined with the green image light Pg and the red image light Pr to generate the image light P. The generated image light P exits from the first prism 91 toward the projection lens unit 80. However, at the third surface 91c of the first prism 91, a part of the blue image light Pb is reflected to become stray light Q, and passes through the second prism 93 and travels toward a part of the area of the DMD 57. The blue image light Pb going to the DMD 57 is about several percent of the blue image light Pb generated in the DMD 59.

[0056] Next, refer to Figure 5 , Figure 7 。 Figure 7 is a perspective view of the light separation and synthesis member 53 used in the display unit 50 in the embodiment, showing the optical path of the green image light Pg reflected by the DMD 55. In addition, in Figure 7 , the light absorption member 61 is omitted for easy understanding of the optical path.

[0057] The green image light Pg generated by reflection from the DMD 55 is totally reflected by the first surface 91a of the first prism 91 and reflected by the third surface 91c. The green image light Pg reflected by the third surface 91c is combined with the blue image light Pb and the red image light Pr to generate the image light P (synthetic light). The generated image light P exits from the first prism 91. However, at the third surface 91c of the first prism 91, a part of the green image light Pg passes through to become stray light Q, and passes through the second prism 93 and travels toward a part of the area of the DMD 57. The green image light Pg going to the DMD 57 is about several percent of the green image light Pg generated in the DMD 55.

[0058] Next, refer to Figure 5 , Figure 8 。 Figure 8 is a perspective view of the light separation and synthesis member 53 used in the display unit 50 in the embodiment, showing the optical path of the red image light Pr reflected by the DMD 57. In addition, in Figure 8 , the light absorption member 61 is omitted for easy understanding of the optical path.

[0059] The red image light Pr reflected by the DMD57 passes through the second prism 93 and is refracted at the first surface 91a of the first prism 91, and then goes toward the first surface 91a. In the refraction at the third surface 91c, the red image light Pr is combined with the blue image light Pb and the green image light Pg to generate the image light P. The generated image light P exits from the first prism 91.

[0060] As described above, the stray light Q derived from the blue image light Pb and the green image light Pg irradiates the DMD57. The irradiation area of the stray light Q becomes the area on the side of the third prism 95 of the DMD57.

[0061] Next, Figure 9 the structures of the DMD55, 57, and 59 will be described. Since the DMD55, 57, and 59 have the same structure, the DMD57 will be taken as an example for description. The DMD57 includes a housing 101, a light modulation unit 103, a cover 105, and a seal 107.

[0062] The housing 101 has an opening 101a, and the inside is hollow to accommodate the light modulation unit 103. The opening 101a is blocked by the cover 105. The inner edge of the opening 101a and the cover 105 are sealed by the seal 107. The cover 105 is a colorless and transparent member, such as glass or resin. The housing 101 is made of a non-metal material, such as ceramic. The seal 107 is made of resin, for example.

[0063] The light modulation unit 103 has a plurality of micromirrors (not shown) arranged in a matrix. The light modulation unit 103 rotates each mirror according to a control signal from the control unit 70, thereby modulating the incident light to generate the image light.

[0064] The red light separated from the white light in the first prism 91 is incident on the DMD57, which is a reflective display element. Similarly, the green light separated from the white light is incident on the DMD55, and the blue light separated from the white light is incident on the DMD59. Each of the DMD55, 57, and 59 is communicably connected to the control unit 70. The light modulation unit 103 modulates the incident light according to a control signal from the control unit 70, and reflects each incident light as the green image light Pg, the red image light Pr, and the blue image light Pb. The color image lights Pg, Pr, and Pb are combined again at the third surface 91c of the first prism 91, and the combined image light P is incident on the projection lens assembly 80. The outgoing light from the projection lens assembly 80 is magnified and projected onto the screen as the image light P.

[0065] However, there is stray light Q where the imaging lights Pg and Pb that can be modulated into imaging signals in DMDs 55 and 59 are not recombined again on the third surface 91c of the first prism 91. This stray light Q travels toward a part of the DMD 57. If this stray light Q irradiates the seal 107, the energy of the stray light Q is converted into heat, melting the seal 107 to form a hole. Due to this hole, the inside and outside of the housing 101 communicate with each other, breaking the airtightness inside the housing 101. As a result, the rotation of each micromirror in the DMD 57 is delayed, and dot missing or the like occurs in the generated red imaging light Pr, thereby degrading the image quality.

[0066] The light absorption member 61 is disposed between the DMD 57 and the second prism 93 and is disposed parallel to the DMD 57 and the fifth surface 93b of the second prism 93. A part of the stray light Q generated in the first prism 91 or the second prism 93 irradiates the light absorption member 61 and is converted into heat by the light absorption member 61. Since the light absorption member 61 is supported in a non-contact state with the DMD 57, the thermal energy converted from light by the light absorption member 61 is not directly transferred to the DMD 57. In addition, the remaining stray light Q enters the light modulation unit 103 of the DMD 57 and is reflected by the micromirror.

[0067] As Figure 9 and Figure 10 shown, the light absorption member 61 has a mask member 61a and a heat dissipation member 61b. The light absorption member 61 covers a part of the DMD 57 other than the light modulation unit 103. The mask member 61a includes, for example, a substantially rectangular plate 61ad having a positioning portion 61ac formed by cutting off one corner. In the central portion of the mask member 61a, a through hole is formed as a light transmission region 61ab, and an antireflection film 61ae covers the opening of the through hole. The antireflection film 61ae includes, for example, silicon dioxide. The size of the light transmission region 61ab is formed corresponding to the display region of the light modulation unit 103 of the DMD 57. The separated red light and the red imaging light Pr are transmitted through the light transmission region 61ab.

[0068] The covering member 61a is, for example, colorless and transparent glass, and a film 61aa is formed on the plate 61ad in the irradiation area where the stray light Q is irradiated. That is, the covering member 61a of the light absorption member 61 includes the plate 61ad and the film 61aa on the plate 61ad. The formed film 61aa is a metal film or a dielectric film. The metal film is, for example, a chromium multilayer film, but other metals can also be used. Regarding the metal multilayer film, for example, it is made into a thin film by dividing it into multiple layers by evaporation or sputtering. The film thickness of the metal multilayer film is about 300 μm. The dielectric film is, for example, a silicon-based film. The thermal conductivity of the glass used as the covering member 61a is 1.3 W / m･K or more, and quartz glass or sapphire glass is used as the covering member 61a, for example. The maximum transmittance of the film 61aa formed in the irradiation area is 20% or less in the wavelength band of light from 420 nm to 630 nm.

[0069] The heat exhaust member 61b has the function of absorbing and exhausting the heat converted from the light absorbed by the covering member 61a irradiated with the stray light Q. The heat exhaust member 61b is arranged in contact with the covering member 61a, and heat is conducted from the covering member 61a to the heat exhaust member 61b. The heat exhaust member 61b is a metal plate with excellent heat conduction, for example, made of copper. In addition, the heat exhaust member 61b can also be directly connected to the plate 61ad of the covering member 61a. Thereby, heat can be further conducted.

[0070] The heat exhaust member 61b has: a recess 61ba for accommodating the covering member 61a; and a rectangular opening 61bb formed in the central portion of the recess 61ba. The opening 61bb is formed larger than the light transmission area 61ab of the covering member 61a, and the separated red light and the red image light Pr pass through.

[0071] Reference Figure 5 To illustrate the function of the light absorption member 61. The green image light Pg modulated from the separated green light by the DMD55 is incident on the first prism 91 again and is totally reflected on the first surface 91a. A part of the totally reflected green image light Pg transmits through the third surface 91c having the function of transmitting blue light and red light. The transmitted green image light Pg becomes the stray light Q and exits from the second prism 93 and irradiates the light absorption member 61.

[0072] In addition, the blue image light Pb modulated from the separated blue light by the DMD59 is incident on the third prism 95 and the second prism 93 again. A part of the light of the blue image light Pb is reflected on the third surface 91c and becomes the stray light Q again and is incident on the second prism 93. The stray light Q originating from the blue image light Pb also exits from the second prism 93 and irradiates the light absorption member 61.

[0073] In this way, the film 61aa of the light absorption member 61 is disposed in the region irradiated with the stray light Q. The stray light Q irradiated onto the film 61aa of the light absorption member 61 is converted into heat energy and dissipated into the air from the light absorption member 61 and the heat dissipation member 61b. Since the film 61aa is disposed to overlap with the seal 107 of the DMD 57 in a plan view, for example, the irradiation of the stray light Q on the seal 107 can be reduced. Thereby, the seal 107 can be prevented from being damaged by heat and the airtightness inside the DMD 57 can be broken.

[0074] [1-2. Effects, etc.]

[0075] As described above, the display device 3 according to the present embodiment includes: a light source unit 10 that irradiates light; and the DMD 57 and the DMD 55. The DMD 57 and the DMD 55 each include a light modulation unit 103 that modulates and reflects incident light. The display device 3 further includes a light separation and synthesis member 53 that separates the light from the light source unit 10 into red light and green light having different wavelength bands. The light separation and synthesis member 53 emits red light to the DMD 57 and green light to the DMD 55, and synthesizes the red image light Pr reflected by the DMD 57 and the green image light Pg reflected by the DMD 55. The display device 3 further includes a light absorption member 61 that covers a part of the DMD 57 other than the light modulation unit 103. The light absorption member 61 absorbs a part of the green image light Pg that is reflected by the DMD 55 and travels to the DMD 57.

[0076] In the present embodiment, since the display device 3 includes the light absorption member 61, the stray light Q irradiated onto the DMD 57 can be reduced. Further, the light absorption member 61 discharges the heat generated by absorbing the stray light Q into the air. Thereby, the reduction in the utilization efficiency of the light irradiated from the light source unit 10 can be suppressed, and the temperature rise of the DMD 57 caused by the stray light can be suppressed. As a result, the display device 3 and the projection device 1 that can suppress the temperature rise of the DMD 57 can be provided.

[0077] (Other embodiments)

[0078] As described above, the above embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited thereto, and can also be applied to embodiments in which changes, replacements, additions, omissions, etc. are made. In addition, the respective constituent elements described in the above embodiments can be combined to form a new embodiment.

[0079] In the embodiment, the covering member 61a and the heat dissipation member 61b are separate members, but it is not limited thereto. In Figure 5 , the heat dissipation member 61b can be given a light absorption function without using the covering member 61a, or the covering member 61a and the heat dissipation member 61b can be integrated.

[0080] In an embodiment, the covering member 61a is a plate-like member having a substantially rectangular shape, but is not limited thereto. As shown in Figure 11 , the covering member 61a may have an L shape, or may have a U shape surrounding the light transmission region 61ab as shown in Figure 12 . Thereby, the manufacturing cost of the light absorption member 61 can be reduced.

[0081] In an embodiment, the heat radiation member 61b radiates heat to the air for heat radiation, but is not limited thereto. A heat pipe may be brought into contact with the heat radiation member 61b, a pipe through which cooling water flows may be brought into contact with the heat radiation member 61b, or the heat radiation efficiency may be improved by blowing the wind of a fan onto the heat radiation member 61b.

[0082] In an embodiment, the light source unit 10 generates white light from a blue laser based on the blue semiconductor laser 11a, but is not limited thereto. White light may also be generated by synthesizing light of respective colors from a red semiconductor laser, a blue semiconductor laser, and a green semiconductor laser, or a light source other than a laser such as a lamp may be used.

[0083] As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the drawings and the detailed description are provided. Therefore, among the components described in the drawings and the detailed description, not only the components necessary for solving the problem are included, but also the components not necessary for solving the problem may be included for exemplifying the above technology. Therefore, these non-essential components should not be directly regarded as essential just because they are described in the drawings and the detailed description.

[0084] In addition, since the above-described embodiments are used to exemplify the technology in the present disclosure, various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or the equivalents thereof.

[0085] (Summary of the Embodiment)

[0086] (1) The display device of the present disclosure includes: a light source unit that irradiates light; and a first reflective display element and a second reflective display element each having a light modulation unit that modulates and reflects incident light. The display device further includes a light separation and synthesis member that separates the light from the light source unit into first light and second light having different wavelength bands, emits the first light to the first reflective display element, emits the second light to the second reflective display element, and synthesizes the modulated first light reflected by the first reflective display element and the modulated second light reflected by the second reflective display element. The display device further includes a light absorption member that covers a part of the first reflective display element other than the light modulation unit and absorbs a part of the modulated second light that is reflected by the second reflective display element and travels toward the first reflective display element.

[0087] In this way, the light absorption member covers a part of the first reflective display element other than the light modulation unit and absorbs a part of the modulated second light that is reflected by the second reflective display element and travels toward the first reflective display element. Therefore, stray light generated due to omission of light synthesis in the light separation and synthesis member can be reduced from entering the first reflective display element. Thereby, a display device capable of suppressing a temperature rise of the display element can be provided.

[0088] (2) The display device of (1) further includes a third reflective display element having a light modulation unit that modulates and reflects incident light. The light separation and synthesis member separates the light from the light source unit into the first light, the second light, and third light having different wavelength bands, emits the third light to the third reflective display element, and synthesizes the modulated first light, the modulated second light, and the modulated third light reflected by the third reflective display element. The light absorption member absorbs a part of the modulated third light that is reflected by the third reflective display element and travels toward the first reflective display element.

[0089] (3) The display device of (2) further includes a heat radiation member that discharges heat generated by the absorbed second light and third light. By providing the heat radiation member, heat generated by the stray light absorbed by the light absorption member can be efficiently discharged.

[0090] (4) In the display device according to any one of (1) to (3), the light absorption member includes a covering member formed by forming a film on a plate. The maximum transmittance of the film formed in the covering member in the wavelength band of light of 420 nm or more and 630 nm or less is 20% or less.

[0091] (5) In the display device of (4), the film is a metal film. Since the film of the light absorption member is a metal film, it has excellent heat resistance and durability, and also has excellent thermal conductivity.

[0092] (6) In the display device of (4), the film is a dielectric film.

[0093] (7) In the display device of (2) or (3), the light separation and combination member is a plurality of integrated prisms.

[0094] (8) In the display device of (7), the prism includes: a triangular prism-shaped first prism having a first surface perpendicular to the emission direction of the combined light; a triangular prism-shaped second prism adjacent to the first prism; and a trapezoidal prism-shaped third prism adjacent to the second prism.

[0095] (9) In the display device of (8), the first prism has: a second surface connected to the first surface and extending parallel to the second reflective display element; and a third surface connected to the first surface and the second surface and in contact with the second prism. The second prism has: a fourth surface in contact with the third surface of the first prism; a fifth surface connected to the fourth surface and extending parallel to the first reflective display element; and a sixth surface connected to the fourth surface and the fifth surface and in contact with the third prism. The third prism includes: a seventh surface in contact with the sixth surface of the second prism; and an eighth surface facing the seventh surface and extending parallel to the third reflective display element.

[0096] (10) In the display device of any one of (1) to (9), the light absorption member has a U shape or an L shape. Thereby, the manufacturing cost of the light absorption member 61 can be reduced.

[0097] (11) It includes: the display device of any one of (1) to (10); and a projection lens unit that projects the image light emitted from the display device.

[0098] The present disclosure can be applied to a projection type image display device such as a light source device or a projector.

Claims

1. A display device, comprising: A light source unit that irradiates light; A first display element having a first light modulation unit that modulates and reflects incident light; A second display element having a second light modulation unit that modulates and reflects incident light; A light separation and synthesis member that separates the light irradiated by the light source unit into first light and second light with different wavelength bands, emits the first light to the first display element, emits the second light to the second display element, and synthesizes the first light reflected and modulated by the first display element and the second light reflected and modulated by the second display element to generate synthesized light; and A light absorption member that covers only a part of the first display element other than the first light modulation unit and absorbs a part of the modulated second light that is reflected by the second display element and travels toward the first display element, The light absorption member includes: A heat dissipation member that discharges heat generated by a part of the absorbed second light.

2. The display device according to claim 1, wherein The light absorption member further includes: A covering member including a sheet and a film on the sheet, The first display element includes: a housing having an opening; a lid that closes the opening; and a seal that seals between the inner edge of the opening and the lid, The film is arranged to overlap the seal of the first display element when viewed from above.

3. The display device according to claim 1, wherein The light absorption member is arranged in a non-contact state with the first display element.

4. The display device according to claim 1, wherein The display device includes: A third display element having a third light modulation unit that modulates and reflects incident light, The light separation and synthesis member separates the light irradiated by the light source unit into the first light, the second light, and the third light with different wavelength bands, emits the third light to the third display element, and synthesizes the modulated first light, the modulated second light, and the third light reflected and modulated by the third display element to generate synthesized light, The light absorption member further absorbs a part of the modulated third light that is reflected by the third display element and travels toward the first display element.

5. The display device according to claim 2, wherein The light transmittance of the film of the covering member is 20% or less in the wavelength band of light of 420 nm or more and 630 nm or less.

6. The display device according to claim 4, wherein The heat dissipation member discharges heat generated by a part of the absorbed third light.

7. The display device according to claim 6, wherein The heat dissipation member is located between the covering member and the first display element.

8. The display device according to claim 2, wherein The film is a metal film.

9. The display device according to claim 2, wherein The film is a dielectric film.

10. The display device according to claim 4, wherein The light separation and synthesis member includes a plurality of integrated prisms.

11. The display device according to claim 10, wherein The plurality of prisms include: The first prism has a first surface perpendicular to the exit direction of the combined light and has a triangular prism shape; The second prism is adjacent to the first prism and has a triangular prism shape; and The third prism is adjacent to the second prism and has a trapezoidal prism shape.

12. The display device according to claim 11, wherein The first prism further has: A second surface connected to the first surface and extending parallel to the second display element; and A third surface connected to the first surface and the second surface and in contact with the second prism, The second prism has: A fourth surface in contact with the third surface of the first prism; A fifth surface connected to the fourth surface and extending parallel to the first display element; and A sixth surface connected to the fourth surface and the fifth surface and in contact with the third prism, The third prism has: A seventh surface in contact with the sixth surface of the second prism; and An eighth surface facing the seventh surface and extending parallel to the third display element.

13. The display device according to claim 1, wherein The light absorption member has a U shape.

14. The display device according to claim 1, wherein The light absorption member has an L shape.

15. The display device according to claim 1, wherein The light source unit irradiates white light.

16. The display device according to claim 1, wherein Each of the first display element and the second display element includes a digital micromirror device.

17. The display device according to claim 1, wherein The wavelength band of the first light includes the wavelength of red light, The wavelength band of the second light includes the wavelength of green light.

18. The display device according to claim 2, wherein The heat radiation member is directly in contact with the plate.

19. The display device according to claim 6, wherein The heat radiation member is made of copper.

20. The display device according to claim 2, wherein The plate is made of glass.

21. The display device according to claim 12, wherein The light separation and combination member is configured such that: A part of the modulated second light is transmitted through the third surface and the second prism and goes to the first display element, A part of the modulated third light is reflected by the third surface and transmitted through the second prism and goes to the first display element.

22. A display device, comprising: A light source unit that irradiates light; A first display element having a first light modulation unit that modulates and reflects incident light; A second display element having a second light modulation unit that modulates and reflects incident light; A third display element having a third light modulation unit that modulates and reflects incident light; An optical separation and synthesis component separates the light irradiated by the light source unit into first light, second light, and third light with different wavelength bands, emits the first light to the first display element, emits the second light to the second display element, emits the third light to the third display element, and synthesizes the first light reflected and modulated by the first display element, the second light reflected and modulated by the second display element, and the third light reflected and modulated by the third display element to generate synthesized light; And A light absorption member that covers a part of the first display element other than the first light modulation unit in a non-contact state with the first display element, and absorbs a part of the modulated second light that is reflected by the second display element and goes to the first display element, The light absorption member further absorbs a part of the modulated third light that is reflected by the third display element and goes to the first display element, The light absorption member includes: A heat dissipation member that discharges heat generated from a part of the second light and a part of the third light that are absorbed. The light absorption member further includes: A covering member including a sheet and a film on the sheet, wherein the light transmittance of the film of the covering member is 20% or less in a wavelength band of light of 420 nm or more and 630 nm or less. The heat dissipation member is located between the covering member and the first display element. The first display element includes: a housing having an opening; a lid that closes the opening; and a seal that seals between an inner edge of the opening and the lid. The film is arranged to overlap the seal of the first display element when viewed from above.

23. A projection device, comprising: The display device according to claim 1; and A projection lens assembly that projects image light emitted from the display device.

Images